Your looking at a sportive bike around the £1k mark basically I guess, there are a few options, im a newby tbh but recently I bought a new bike with the same uses in mind as you.
I rode the Trek 2.1, personally I didnt like it, spec wise and price wise its a good deal, its mostly 105 groupset with tiagra brakes. Looks nice etc. But imo wasnt very comfy, I cant tell handling form one bike to the next in this price range (like most newbys cant) but it did feel drasticaly different to other bikes I tried, it felt a lot more "rumbley" and less stuck to the road in my opinion. I also tried one of the higher end Trek's for sizing (Carbon Madone, not sure of the exact one) didnt like that either. I went for a Cannondale caad9 with tiagra groupset, I decided to plunk for lesser group for a frame that felt much nicer to me.
All in all try the £1k mark bikes from all the major brands and see what you like best, I gathered during my search for that price you will basically be choosing on appearence and feel on the most part, they will all be good bikes. You can always upgrade the groupset if you choose a lesser one initially to get a nicer frame for your budget.
Good 1k bikes I know of,
Cannondale CAAD9 w Tiagra
Cannondale CAAD8 w 105
Boardman Team-carbon w SRAM Rival?(only available at
Halfords and online, its meant to be a great bike, Halfords puts people off, inc me)
Boardman Team w SRAM Rival (same as the Team-carbon but aluminium frame, only £800, also only available at Halfords and online)
Trek 2.1 w 105 & Tiagra Brakes
Trek 1.5 w Tiagra
Then there is the Scotts, Specialized's, Genesis bikes all in that range you may consider.
You need to ride them to know what you like. If your on the thing for 100 miles you wont be very concerned about other peoples opinions by the end of the day
I didnt realise how different bikes could feel in the same price range.